We know how certain things in DNA of humans alive today map to features, measurements, etc. Finding some bones/skulls also helps a lot. It's probably not that

We know how certain things in DNA of humans alive today map to features, measurements, etc. Finding some bones/skulls also helps a lot. It's probably not that accurate though, like you would be able to tell what Denisovans looked like generally, but not what a Denisovan looked like with any accuracy. For modern human individuals it's pretty limited to 'obvious' traits like eye color, hair color, and skin color. There was some projects that tried to chart beyond that, but the results are just... ok: https://www.pnas.org/content/114/38/10166 https://www.pnas.org/content/114/38/10166 You might be able to pick someone out of a hundred with that (check Fig. 2 for an example).